The invention relates to a new land marking device.
Most land surveys are performed utilizing either optical survey instruments or satellite-based, Global Positioning System (GPS) survey equipment. In traditional surveys, a line of sight must be secured in order to perform the survey. GPS survey techniques require a relatively unobstructed signal path between a reference or relay station, a satellite network and the GPS receiver. However, in some terrain, maintaining a line of sight or GPS signal quality can be difficult or impractical. Specifically, forested areas and hilly terrain provide examples of terrain that can present difficulties utilizing traditional methods of conducting the two types of surveys noted above as both types of geography obstruct either line of sight or signal strength between the satellite and/or reference station.
In the case of forested area, ground-base land surveys using optical survey equipment or GPS are difficult if not impossible in areas with trees or other vegetative cover. As such, forest cover must almost always be removed prior to the commencement of a survey of such an area. This requires use of hand-cutting or bulldozing, or a combination of the two. This can be exceedingly expensive, require a massive amount of personnel on the ground and be relatively time consuming. Alternatively, while there are methods of surveying such areas without the need to clear a line of sight, these avoidance surveys are prohibitively time consuming for many applications. As such, they fail, in most cases, to provide a cost-effective means of surveying. Moreover, avoidance surveys sacrifice accuracy. For many applications, the accuracy lost is not acceptable. Sufficient accuracy has traditionally only been achievable by clearing a line of sight.
Surveys through geographically hilly regions can also present difficulties. In these cases, alternate techniques that are relatively slow and costly must be employed to compensate for the inability to maintain a line of sight or GPS signal strength through such regions. The techniques include alternating optical survey methods, and, in some cases, incorporating inertial/GPS and barometric surveys.
Surveys encountering swamps or muskeg terrain conditions or other geographically difficult terrain including ditches, ravines, fence lines, streams or rivers, buildings etc. can be expensive, dangerous and/or time consuming. In the case of swamp or muskeg terrain, any planned surveys are, in many cases, postponed until the terrain of such areas has frozen. Of course, this further assumes that this is an environmental possibility in the area of interest.
In the case of geographic variability over a survey area, such as ditches, ravines, fence lines, streams or rivers, buildings, by way of example, a survey team must, at the same time, negotiate these obstacles during a survey. This slows the survey.
The present invention provides a land marking device to be incorporated into new system and method of aerial land surveying and land marking free of the disadvantages and limitations noted above.
It is an object of the present invention to provide a new land marking device, to be used in surveying and land marking in association with a new method of land marking.
According to one aspect of the invention, there is provided a land marking device capable of marking a survey point on the ground. The device comprises: (a) a housing adapted to be suspended from an aircraft; (b) a receptacle inside the housing, the receptacle being adapted to accommodate at least one marker in the form of a rigid elongated member, and (c) a mechanism cooperating with the receptacle for ejecting the marker from the receptacle towards the survey point, when the housing is positioned above the survey point, the mechanism being capable of applying sufficient force to the rigid elongated marker in the lengthwise direction of the marker as to propel the marker lengthwise toward the survey point with sufficient momentum as to partially penetrate the ground at or near the survey point on the ground whereby the survey point is securely marked.
The invention disclosed is a land marking device that may be used in association with the above-noted new system and method of land marking where the device is capable of marking a point on the ground. The device is comprised of an aerodynamically designed external shell that allows the device to remain stable when suspended from an aircraft. It also includes at lease one receptacle inside the shell where the receptacle accommodates a marker and provides for a means within the shell capable of ejecting the marker from the receptacle towards a point on the ground when the device is positioned above the point in question such that the ejected marker is secured at or near the point on the ground.
A further embodiment of the invention includes a bumper skirt designed to protect the shell during descent into its position above the point on the ground and its removal from that point to a subsequent point on the ground.
A further embodiment of the invention specifically provides for a receptacle that is an elongate tube.
A further embodiment of the invention provides for a marker that is a dowel.
A further embodiment of the invention provides for a hammer mechanism as the means for ejecting the marker.
A further embodiment of the invention provides for a tensioning means to drive the hammer mechanism.
A further embodiment of the invention provides for a steel spring as the tensioning means.
One of many advantages of the land marking device is that it provides, in combination with the aircraft and surveying means, a surveying method wherein a GPS signal may be maintained from the air and used to record a location of interest on the ground while the land marking device provides a marker on that location point. This is useful in a forested, obstructed or hilly survey area. Costs of such a survey should be reduced in so far as costs arising from the requirement to remove physical obstacles obstructing a line of sight or GPS signal quality is eliminated. For example, when surveying in a densely forested area, timber need not be cleared prior to the survey. This can result in savings on the order of several thousands of dollars per kilometer of surveyed area. Moreover, this results in significant environmental benefits as well as economic benefits. Also, the time required to conduct the survey through an area heavily forested or defined by hilly geography is greatly reduced.
Also, the method and system for aerially marking the ground using the subject invention is quicker and competitive with ground-based surveys where geographic obstructions arise on a survey site that slow ground-based crews. The use of the air-based land marking device will result in a survey that is not affected by difficulties in accessing and maneuvering through surveyed locations with obstacles, such as swamps, ravines, streams, buildings, fences, rivers, ditches, etc. The ground staking device is capable of laying out and recording a large amount of survey data in difficult or variable terrain in a relatively short time period when compared with conventional ground-based survey instruments. It is estimated that the land marking device, when used in association with an aircraft, provides for a surveying method wherein an area can be surveyed in a fraction of the time required to conduct a ground-based optical survey with little or no penalty in the accuracy of the resulting survey.
The land marking device can be utilized in many contexts, such as, by way of example, the oil and gas industry, civil engineering, mining and forestry. It can be applied, for example, to marking and/or surveying of boundaries, pipelines, oil/gas leases, seismic lines, open pit mines, roads, creek crossings, ordinary line features, etc. It can be used in all applications when land marking and/or surveying is carried out using traditional measuring and marking devices.